Semiconductor device and method for fabricating the same

ABSTRACT

A semiconductor device includes a substrate including a first active region, a second active region and a field region between the first and second active regions, and a gate structure formed on the substrate to cross the first active region, the second active region and the field region. The gate structure includes a p type metal gate electrode and an n-type metal gate electrode directly contacting each other, the p-type metal gate electrode extends from the first active region less than half way toward the second active region.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/683,525, filed on Apr. 10, 2015, and U.S. patent application Ser. No.14/165,930, filed on Jan. 28, 2014, now U.S. Pat. No. 9,048,219, issuedon Jun. 2, 2015, which claims priority from Korean Patent ApplicationNo. 10-2013-0082936 filed on Jul. 15, 2013 in the Korean IntellectualProperty Office, and all the benefits accruing therefrom under 35 U.S.C.119, the contents of which in its entirety are herein incorporated byreference.

BACKGROUND

1. Field

Exemplary embodiments of inventive concepts relate to a semiconductordevice and a method for fabricating the same.

2. Related Art

As semiconductor manufacturers reduce geometries of semiconductordevices in order to continue providing more functionality andperformance in smaller and smaller packages, reduced features sizes mayaffect the performance of the semiconductor devices. For example, thedimensions of a MOS device's gate region may be reduced and,consequentially, the distance between source and drain regions formed atopposite sides of the gate region will be reduced. Such a reduction mayaffect various performance characteristics such a device.

SUMMARY

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device including a substrate includinga first active region, a second active region and a field region betweenand directly contacting the first and second active regions; and a gatestructure formed on the substrate to cross the first active region, thesecond active region and the field region, wherein the gate structureincludes a p-type metal gate electrode and an n-type metal gateelectrode directly contacting each other, wherein the p-type metal gateelectrode is formed on the first active region and the n-type metal gateelectrode is formed on the second active region, and wherein the contactsurface between the p-type metal gate electrode and the n-type metalgate electrode is closer to the first active region than to the secondactive region.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device, wherein the field region has acenter line equidistantly spaced apart from the first active region andthe second active region, and the p-type metal gate electrode does notextend to the center line.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device of claim 1, wherein the p-typemetal gate electrode includes a p-type work function adjusting layer, afirst lower metal gate electrode and a first upper metal gate electrode,sequentially formed one on another, and the n-type metal gate electrodeincludes a second lower metal gate electrode and a second upper metalgate electrode sequentially formed one on the other, but not includingthe p-type work function adjusting layer.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the contact surface isdefined by the p-type work function adjusting layer.

Exemplary embodiments in accordance with principles of inventiveconcepts include semiconductor device wherein the first lower gateelectrode and the second lower gate electrode are in direct contact withone another, and the first upper gate electrode and the second uppergate electrode are in direct contact with one another.

Exemplary embodiments in accordance with principles of inventiveconcepts include semiconductor device including an interlayer dielectriclayer formed on the substrate and including a trench intersecting thefirst active region, the field region and the second active region,wherein the first lower gate electrode and the second lower gateelectrode are formed along sidewalls and a bottom surface of the trench.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the first lower gateelectrode and the second lower gate electrode are separated from eachother by the p-type work function adjusting layer.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the substrate is asilicon substrate, and a silicon germanium channel layer is providedbetween the first active region and the p-type metal gate electrode.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the first active regionis a pull-up transistor forming region of a static random access memory(SRAM) and the second active region is a pull-down transistor formingregion of an SRAM.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the first active regionand the second active region are a first fin type active pattern and asecond fin type active pattern, respectively.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device including a substrate includinga first active region, a second active region and a field region betweenand directly contacting the first and second active regions; aninterlayer dielectric layer formed on the substrate, including a trenchintersecting the first active region, the field region and the secondactive region; and a gate structure formed in the trench to intersectthe first active region, the second active region and the field regionand having a top surface coplanarly formed with the interlayerdielectric layer, wherein the gate structure includes a p type metalgate electrode and an n-type metal gate electrode directly contactingeach other, and a contact surface formed between the p-type metal gateelectrode and the n-type metal gate electrode wherein the p-type metalgate electrode is formed on the first active region and the n-type metalgate electrode is formed on the second active region, and wherein afirst width ranging from the contact surface to the first active regionis less than a second width ranging from the contact surface to thesecond active region.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the p-type metal gateelectrode and the n-type metal gate electrode are in direct contact withone another.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the field region has acenter line equidistantly spaced apart from the first active region andthe second active region, and the contact surface is positioned betweenthe center line and the first active region.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the p-type metal gateelectrode includes a p-type work function adjusting layer, a first lowermetal gate electrode and a first upper metal gate electrode,sequentially formed one on another, and the n-type metal gate electrodeincludes a second lower metal gate electrode and a second upper metalgate electrode sequentially formed one on the other, but not includingthe p-type work function adjusting layer.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device comprising a gate dielectriclayer formed between the substrate and the p-type metal gate electrodeand between the substrate and the n-type metal gate electrode, and thegate dielectric layer is formed along a bottom surface of the trench,but not formed on sidewalls of the trench.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the p-type work functionadjusting layer has a first part formed along the gate dielectric layerand a second part extending in a direction normal to the substrate andformed on the field region, and the second part of the p-type workfunction adjusting layer is interposed between the first lower gateelectrode and the second lower gate electrode.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device comprising a gate dielectriclayer formed between the substrate and the p-type metal gate electrodeand between the substrate and the n-type metal gate electrode, and thegate dielectric layer is formed along sidewalls and a bottom surface ofthe trench.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the p-type work functionadjusting layer includes at least one of TiN and TaN.

Exemplary embodiments in accordance with principles of inventiveconcepts include semiconductor device including a first fin type activepattern; a second fin type active pattern adjacent to the first fin typeactive pattern; an isolation layer formed between and making directcontact with the first fin type active pattern and the second fin typeactive pattern; and

a gate structure intersecting the first fin type active pattern, theisolation layer and the second fin type active pattern, wherein the gatestructure includes a p-type metal gate electrode and an n-type metalgate electrode directly contacting each other wherein the p-type metalgate electrode is formed on the first fin type active pattern, and then-type metal gate electrode is formed on the second fin type activepattern, and wherein a contact surface between the p-type metal gateelectrode and the n-type metal gate electrode is closer to the first fintype active pattern than to the second fin type active pattern.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the p-type metal gateelectrode includes a p-type work function adjusting layer, a first lowermetal gate electrode and a first upper metal gate electrode,sequentially formed one on another, and the n-type metal gate electrodeincludes a second lower metal gate electrode and a second upper metalgate electrode sequentially formed one on the other, but not includingthe p-type work function adjusting layer, and the contact surface isdefined by the p-type work function adjusting layer.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the first lower gateelectrode and the second lower gate electrode are in direct contact withone another, and the first upper gate electrode and the second uppergate electrode are in direct contact with one another.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the first lower gateelectrode and the second lower gate electrode are separated from eachother by the p-type work function adjusting layer.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the first fin typeactive pattern is a silicon element semiconductor, and a silicongermanium channel layer is provided between the first fin type activepattern and the p-type metal gate electrode, wherein the silicongermanium channel layer is formed along at least a portion of the firstfin type active pattern.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the first fin typeactive pattern includes at least one of a silicon germanium layer and agermanium layer.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the second fin typeactive pattern includes a group III-V compound semiconductor layer.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device including a gate structureformed over sequentially arranged first active, field, and second activeregions in a substrate; and a p-type metal gate electrode in the gatestructure extending from over the first active region less than half waytoward the second active region.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device including an n-type metal gateelectrode in the gate structure extending from over the second activeregion to greater than half way toward the first active region.

Exemplary embodiments in accordance with principles of inventiveconcepts include semiconductor device including a gate structure formedover sequentially arranged first active, field, and second activeregions in a substrate; a p-type metal gate electrode in the gatestructure extending from over the first active region; and an n-typemetal gate electrode in the gate structure extending from over thesecond active region, the n-type and p-type metal gate electrodesarranged to increase the threshold voltage of the semiconductor device.

Exemplary embodiments in accordance with principles of inventiveconcepts include a semiconductor device wherein the p-type metal gatestructure extends over the first active region less than half way towardthe second active region and the n-type metal gate electrode in the gatestructure extends more than half way towards the first active region.

Exemplary embodiments in accordance with principles of inventiveconcepts include a memory device including a semiconductor deviceincluding a gate structure formed over sequentially arranged firstactive, field, and second active regions in a substrate; a p-type metalgate electrode in the gate structure extending from over the firstactive region; and an n-type metal gate electrode in the gate structureextending from over the second active region, the n-type and p-typemetal gate electrodes arranged to increase the threshold voltage of thesemiconductor device.

Exemplary embodiments in accordance with principles of inventiveconcepts include a portable electronic device including a semiconductordevice including a gate structure formed over sequentially arrangedfirst active, field, and second active regions in a substrate; a p-typemetal gate electrode in the gate structure extending from over the firstactive region; and an n-type metal gate electrode in the gate structureextending from over the second active region, the n-type and p-typemetal gate electrodes arranged to increase the threshold voltage of thesemiconductor device.

Exemplary embodiments in accordance with principles of inventiveconcepts include a memory cellular telephone including a semiconductordevice including a gate structure formed over sequentially arrangedfirst active, field, and second active regions in a substrate; a p-typemetal gate electrode in the gate structure extending from over the firstactive region; and an n-type metal gate electrode in the gate structureextending from over the second active region, the n-type and p-typemetal gate electrodes arranged to increase the threshold voltage of thesemiconductor device.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of exemplary embodiments ofinventive concepts will become more apparent by describing in detailpreferred embodiments thereof with reference to the attached drawings inwhich:

FIG. 1 is a plan view illustrating semiconductor devices according tofirst to fourth exemplary embodiments of inventive concepts;

FIG. 2 is a cross-sectional view illustrating the semiconductor deviceaccording to the first embodiment of inventive concepts;

FIG. 3 is a cross-sectional view illustrating the semiconductor deviceaccording to the second embodiment of inventive concepts;

FIG. 4 is a cross-sectional view illustrating the semiconductor deviceaccording to the third embodiment of inventive concepts;

FIG. 5 is a cross-sectional view illustrating the semiconductor deviceaccording to the fifth embodiment of inventive concepts;

FIG. 6 is a perspective view illustrating semiconductor devicesaccording to fifth and sixth embodiments of inventive concepts;

FIG. 7 is a cross-sectional view illustrating the semiconductor deviceaccording to the fifth embodiment of inventive concepts;

FIG. 8 is a cross-sectional view illustrating the semiconductor deviceaccording to the sixth embodiment of inventive concepts;

FIG. 9 is a perspective view illustrating a semiconductor deviceaccording to a seventh embodiment of inventive concepts;

FIG. 10 is a cross-sectional view illustrating the semiconductor deviceaccording to the seventh embodiment of inventive concepts;

FIGS. 11 and 12 are a circuit view and a layout view illustrating asemiconductor device according to an eighth embodiment of inventiveconcepts;

FIG. 13 is a block diagram of an electronic system includingsemiconductor devices according to some embodiments of inventiveconcepts;

FIGS. 14 and 15 illustrate an exemplary semiconductor system to whichsemiconductor devices according to some embodiments of inventiveconcepts can be employed;

FIGS. 16 to 21 illustrate intermediate process steps in a method forfabricating the semiconductor device according to the third embodimentof inventive concepts;

FIGS. 22 to 25 illustrate intermediate process steps in a method forfabricating the semiconductor device according to the fourth embodimentof inventive concepts; and

FIGS. 26 to 30 illustrate intermediate process steps in a method forfabricating the semiconductor device according to the fifth embodimentof inventive concepts.

DESCRIPTION

Various exemplary embodiments will be described more fully hereinafterwith reference to the accompanying drawings, in which exemplaryembodiments are shown. Exemplary embodiments may, however, be embodiedin many different forms and should not be construed as limited toexemplary embodiments set forth herein. Rather, these exemplaryembodiments are provided so that this disclosure will be thorough, andwill convey the scope of exemplary embodiments to those skilled in theart. In the drawings, the sizes and relative sizes of layers and regionsmay be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numerals refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items. The term“or” is used in an inclusive sense unless otherwise indicated.

It will be understood that, although the terms first, second, third, forexample. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another region, layer or section. In this manner, a firstelement, component, region, layer or section discussed below could betermed a second element, component, region, layer or section withoutdeparting from the teachings of exemplary embodiments.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. In this manner, the exemplary term “below” can encompassboth an orientation of above and below. The device may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexemplary embodiments only and is not intended to be limiting ofexemplary embodiments. As used herein, the singular forms “a,” “an” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Exemplary embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized exemplary embodiments (and intermediate structures). As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. In this manner, exemplary embodiments should not be construedas limited to the particular shapes of regions illustrated herein butare to include deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. In this manner, the regions illustrated in the figures areschematic in nature and their shapes are not intended to illustrate theactual shape of a region of a device and are not intended to limit thescope of exemplary embodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which exemplary embodiments belong. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, exemplary embodiments in accordance with principles ofinventive concepts will be explained in detail with reference to theaccompanying drawings.

FIG. 1 is a plan view illustrating semiconductor devices according tofirst to fourth exemplary embodiments in accordance with principles ofinventive concepts. FIGS. 2 through 5 are cross-sectional views ofsemiconductor devices according to first through fourth exemplaryembodiments of inventive concepts, respectively.

Referring to FIG. 1, each of the semiconductor devices 1 to 4 includes asubstrate 10 including a first active region 20, a second active region30, a field region 40, and a gate structure 50 intersecting the firstactive region 20, the second active region 30 and the field region 40.

The substrate 10 may be bulk silicon or a silicon-on-insulator (SOI),for example, or may be a silicon substrate, or a substrate made of othermaterials selected from the group consisting of, for example, germanium,silicon germanium, indium antimonide, lead telluride compound, indiumarsenide, indium phosphide, gallium arsenide, and gallium antimonide,but inventive concepts are not limited thereto.

The first active region 20 and the second active region 30 may bedefined by the field region 40. The first active region 20 and thesecond active region 30 are spatially separated from each other by thefield region 40. First and second active regions (for example, 20, 30)may be referred to herein as being “adjacent” one another. Activeregions are adjacent in the sense that, although field region 40 liesbetween them (and they are, therefore, not adjacent in the sense thatthey abut one another), no active pattern lies between them. Inexemplary embodiments in accordance with principles of inventiveconcepts, first active region 20 and second active region 30 are of arectangular shape elongate in a second direction DR2. The first activeregion 20 and the second active region 30 are arranged in parallel toeach other in long side directions.

The first active region 20 is a PMOS forming region and the secondactive region 30 is an NMOS forming region. The first active region 20may be implemented as a pull up transistor of SRAM and the second activeregion 30 may be implemented as a pull down transistor or a passtransistor of SRAM, for example. In exemplary embodiments in accordancewith principles of inventive concepts, first active region 20 and secondactive region 30 may be PMOS and NMOS forming regions, to which a gatevoltage may be applied by one gate structure.

The first active region 20 and the second active region 30 may be fintype active patterns, for example, which will be described in greaterdetail in the discussion related to FIGS. 6 through 10.

The field region 40 may be formed to surround the first active region 20and the second active region 30, for example, or may be a portionpositioned between the first active region 20 and the second activeregion 30, for example.

The field region 40 is disposed between the first active region 20 andthe second active region 30 while making direct contact with the firstactive region 20 and the second active region 30. That is, in exemplaryembodiments in accordance with principles of inventive concepts, noactive region intervenes between the field region 40 and the firstactive region 20 and between the field region 40 and the second activeregion 30.

The field region 40 may include, for example, at least one of a siliconoxide layer, a silicon nitride layer, a silicon oxynitride layer, orcombinations thereof.

The width of the field region 40 positioned between the first activeregion 20 and the second active region 30 may be denoted by W and mayhave a center line CL equidistantly spaced apart from the first activeregion 20 and the second active region 30. That is, in exemplaryembodiments in accordance with principles of inventive concepts, thedistance between the center line CL and the first active region 20 andthe distance between the center line CL and the second active region 30may be equal, at half the width of the field region 40. The center lineCL of the field region 40 may be parallel to the elongate direction ofthe first active region 20 and the second active region 30.

In exemplary embodiments in accordance with principles of inventiveconcepts, gate structure 50 may be formed on the substrate 10 tointersect the first active region 20, the second active region 30 andthe field region 40. The gate structure 50 may extend lengthwise in afirst direction DR1.

In exemplary embodiments in accordance with principles of inventiveconcepts, gate structure 50 includes a first metal gate electrode 120and a second metal gate electrode 220. The first metal gate electrode120 and the second metal gate electrode 220 may directly contact eachother. The first metal gate electrode 120 is a p-type metal gateelectrode, which is formed on the first active region 20. The secondmetal gate electrode 220 is an n-type metal gate electrode, which isformed on the second active region 30. That is, a PMOS 10 p (alsoreferred to herein as a PMOS transistor) is formed at an intersection ofthe first active region 20 and the gate structure 50, and an NMOS 10 n(also referred to herein as an NMOS transistor) is formed at anintersection of the second active region 30 and the gate structure 50.

Because, in exemplary embodiments in accordance with principles ofinventive concepts, the first metal gate electrode 120 extends on thefield region 40, it may overlap with the first active region 20 and aportion of the field region 40. Because the second metal gate electrode220 directly contacts the first metal gate electrode 120, it may overlapthe second active region 30 and the portion of the field region 40 notoverlapping with the first metal gate electrode 120.

In exemplary embodiments in accordance with principles of inventiveconcepts, gate structure 50 includes a contact surface MI contacting thefirst metal gate electrode 120 and the second metal gate electrode 220.The contact surface MI of the first metal gate electrode 120 and thesecond metal gate electrode 220 is positioned on the field region 40.The contact surface MI positioned between the first metal gate electrode120 and the second metal gate electrode 220 is positioned closer to thefirst active region 20 than to the second active region 30. Because, inexemplary embodiments in accordance with principles of inventiveconcepts, the first active region 20, the contact surface MI, the centerline CL and the second active region 30 are arranged in that order, thefirst metal gate electrode 120 may not overlap with the center line CLof the field region 40. That is, the contact surface MI is positionedbetween the first active region 20 and the center line CL of the fieldregion 40.

A portion of the first metal gate electrode 120 extending on the fieldregion 40 has a first width W1. That is, the first width W1 refers tothe width of the first metal gate electrode 120 ranging from the contactsurface MI to the first active region 20. A portion of the second metalgate electrode 220 extending on the field region 40 has a second widthW2. That is, the second width W2 refers to the width of the second metalgate electrode 220 ranging from the contact surface MI to the secondactive region 30. Because, in exemplary embodiments in accordance withprinciples of inventive concepts, the contact surface MI between thefirst metal gate electrode 120 and the second metal gate electrode 220is closer to the first active region 20 than to the second active region30, the second width W2 is greater than the first width W1.

Because, in exemplary embodiments in accordance with principles ofinventive concepts, the first metal gate electrode 120 and the secondmetal gate electrode 220 directly contact each other, the sum of thewidth W1 of the first metal gate electrode 120 overlapping the fieldregion 40 and the width W2 of the second metal gate electrode 220overlapping the field region 40 may be equal to the width W of the fieldregion 40.

Next, a semiconductor device according to the first exemplary embodimentin accordance with principles of inventive concepts will be describedwith reference to FIGS. 1 and 2.

FIG. 2 is a cross-sectional view illustrating a semiconductor deviceaccording to the first exemplary embodiment of in accordance withprinciples of inventive concepts, taken along lines A-A, B-B and C-C ofFIG. 1.

Referring to FIGS. 1 and 2, the semiconductor device 1 includes thesubstrate 10, the gate dielectric layers 110 and 210 and the gatestructure 50.

The substrate 10 includes the first active region 20, the second activeregion 30 and the field region 40 positioned between the first activeregion 20 and the second active region 30. The field region 40 makesdirect contact with the first active region 20 and the second activeregion 30.

The gate dielectric layers 110 and 210 are formed on the substrate. Thegate dielectric layers 110 and 210 may include the first gate dielectriclayer 110 and the second gate dielectric layer 210. The first gatedielectric layer 110 is formed on the first active region 20 and thesecond gate dielectric layer 210 is formed on the second active region30. The first gate dielectric layer 110 and the second gate dielectriclayer 210 may be defined by the contact surface MI of the gate structure50. The first gate dielectric layer 110 and the second gate dielectriclayer 210 are formed on the same level. By, “formed on the same level”we mean that two elements are formed by the same fabrication process, orprocess step.

Each of the first and second gate dielectric layers 110 and 210 mayinclude a high-k layer, and examples thereof may include, but are notlimited to, at least one of hafnium oxide, hafnium silicon oxide,lanthanum oxide, lanthanum aluminum oxide, zirconium oxide, zirconiumsilicon oxide, tantalum oxide, titanium oxide, barium strontium titaniumoxide, barium titanium oxide, strontium titanium oxide, yttrium oxide,aluminum oxide, lead scandium tantalum oxide, and lead zinc niobate.

The gate structure 50, including the first metal gate electrode 120 andthe second metal gate electrode 220 directly contacting each other, areformed on the gate dielectric layers 110 and 210. The first metal gateelectrode 120 includes the p-type work function adjusting layer 122, thefirst lower metal gate electrode 124 and the first upper metal gateelectrode 126, which are sequentially formed on the first gatedielectric layer 110. The second metal gate electrode 220 includes thesecond lower metal gate electrode 224 and the second upper metal gateelectrode 226, which are sequentially formed on the second gatedielectric layer 210. In this exemplary embodiment in accordance withprinciples of inventive concepts, the second metal gate electrode 220does not include the p-type work function adjusting layer 122.

Because the first metal gate electrode 120 includes the p-type workfunction adjusting layer 122 but the second metal gate electrode 220does not include the p-type work function adjusting layer 122, thecontact surface MI between the first metal gate electrode 120 and thesecond metal gate electrode 220 is defined by the p-type work functionadjusting layer 122. That is, when the gate structure 50 is cut along anormal of the substrate 10 up to an end of the p-type work functionadjusting layer 122 extending on the field region 40, the contactsurface MI is formed between the first metal gate electrode 120 and thesecond metal gate electrode 220.

Because the contact surface MI between the first metal gate electrode120 and the second metal gate electrode 220 is closer to the firstactive region 20 than to the second active region 30, the p-type workfunction adjusting layer 122 does not overlap with the center line CL ofthe field region 40.

The p-type work function adjusting layer 122 extending on the fieldregion 40 while intersecting the first active region 20 may overlap witha portion of the field region 40, and an overlapping width between thep-type work function adjusting layer 122 and the field region 40corresponds to the first width W1 and, as a result, a non-overlappingwidth between the p-type work function adjusting layer 122 and the fieldregion 40 corresponds to the second width W2, obtained by subtractingthe first width W1 from the width W of the field region 40.

Because an interlayer dielectric layer covering the gate structure 50 isformed after forming the gate structure 50, a height of the first metalgate electrode 120 on the first active region 20 is greater than that ofthe second metal gate electrode 220 on the second active region 30second metal gate electrode 220. The difference between the heights ofthe first metal gate electrode 120 and the second metal gate electrode220 is substantially equal to thickness of the p-type work functionadjusting layer 122.

In exemplary embodiments in accordance with principles of inventiveconcepts, first lower metal gate electrode 124 and the second lowermetal gate electrode 224 are directly connected to each other and thefirst upper metal gate electrode 126 and the second upper metal gateelectrode 226 are directly connected to each other. In addition, thefirst lower metal gate electrode 124 and the second lower metal gateelectrode 224 are formed on the same level, and the first upper metalgate electrode 126 and the second upper metal gate electrode 226 arealso formed on the same level.

Because the first lower metal gate electrode 124 and the second lowermetal gate electrode 224 are directly connected to each other, portionsof the first lower metal gate electrode 124 and the second lower metalgate electrode 224 extend onto the field region 40. Because the contactsurface MI is defined by the p-type work function adjusting layer 122,the width W1 of the first lower metal gate electrode 124 extending ontothe field region 40 is smaller than the width W2 of the second lowermetal gate electrode 224 extending onto the field region 40.

The p-type work function adjusting layer 122 may include, for example,at least one of TiN, TaC, TaN and TaCN. The first lower metal gateelectrode 124 and the second lower metal gate electrode 224 may include,for example, at least one of TiN, TaN, TaC, TaCN, TiAl, and TiAlC, andthe first upper metal gate electrode 126 and the second upper metal gateelectrode 226 may include, for example, at least one of Al and W.

A first source/drain 130 may be formed at each side of the first metalgate electrode 120, and a second source/drain 230 may be formed at eachside of the second metal gate electrode 220. In exemplary embodiments inaccordance with principles of inventive concepts, embodiment, the firstsource/drain 130 and the second source/drain 230 are formed in the firstactive region 20 and the second active region 30, respectively, butaspects of inventive concepts are not limited thereto. That is, thefirst source/drain 130 and the second source/drain 230 may protrude froma top surface of the substrate 10, for example.

The semiconductor device 2 according to the second exemplary embodimentin accordance with principles of inventive concepts will now bedescribed with reference to FIGS. 1 and 3. The following descriptionwill focus on differences between the first and second exemplaryembodiments in accordance with principles of inventive concepts.

FIG. 3 is a cross-sectional view illustrating the semiconductor deviceaccording to the second exemplary embodiment in accordance withprinciples of inventive concepts, taken along lines A-A, B-B and C-C ofFIG. 1.

Referring to FIG. 3, the semiconductor device 2 according to the secondexemplary embodiment in accordance with principles of inventive conceptsfurther includes a channel layer 115 formed between the first activeregion 20 and the first metal gate electrode 120. In detail, the channellayer 115 is formed between the first active region 20 and the firstgate dielectric layer 110.

The channel layer 115 may include a material for forming the firstactive region 20, that is, a different material from the substrate 10.Since the PMOS 10 p is formed at the intersection of the first activeregion 20 and the first metal gate electrode 120, the channel layer 115may include a material capable of improving mobility of holes.

In order to improve the mobility of holes in the channel layer 115, thechannel layer 115 may be subjected to compressive stress applied fromthe first active region 20. For example, the channel layer 115 mayinclude a material having a greater lattice constant than the firstactive region 20 in order to apply such stress.

In the semiconductor device 2 according to the second exemplaryembodiment in accordance with principles of inventive concepts, thesubstrate 10 may be a silicon substrate. Because the substrate 10 is asilicon substrate, the first active region 20 may also include silicon.Therefore, the channel layer 115 may include silicon germanium (SiGe)having a greater lattice constant than silicon (Si). That is, inexemplary embodiments in accordance with principles of inventiveconcepts, the channel layer 115 may be a silicon germanium channellayer.

Hereinafter, the semiconductor device 3 according to the third exemplaryembodiment in accordance with principles of inventive concepts will bedescribed with reference to FIGS. 1 and 4. The following descriptionwill focus on differences between the first and third exemplaryembodiments.

FIG. 4 is a cross-sectional view illustrating the semiconductor deviceaccording to the third exemplary embodiment, taken along lines A-A, B-Band C-C of FIG. 1.

Referring to FIG. 4, the semiconductor device 3 according to the thirdexemplary embodiment is formed on the substrate 10 and further includesan interlayer dielectric layer 80 including a trench 85.

The trench 85 intersects the first active region 20, the field region 40and the second active region 30. The first gate dielectric layer 110 andthe second gate dielectric layer 210 are formed on a bottom surface ofthe trench 85. However, the first gate dielectric layer 110 and thesecond gate dielectric layer 210 are not formed on sidewalls of thetrench 85.

The interlayer dielectric layer 80 may include, for example, at leastone of a low-k material, oxide, nitride, and oxynitride. The low-kmaterial may include, for example, may include flowable oxide (FOX),tonen silazene (TOXZ), undoped silicate glass (USG), borosilicate glass(BSG), phosphosilicate glass (PSG), borophosphosilicate glass (BPSG),plasma-enhanced tetraethylorthosilicate (PE-TEOS), fluorosilicate glass(FSG), high density plasma (HDP) oxide, plasma enhanced oxide (PEOX),flowable CVD (FCVD), and combinations thereof.

The gate structure 50 may be formed in the interlayer dielectric layer80 by filling the trench 85. A top surface of the gate structure 50formed in the trench 85 is coplanar with the interlayer dielectric layer80. The first metal gate electrode 120 may be formed by filling a firstpart (85 a of FIG. 17) of the trench 85, and the second metal gateelectrode 220 may be formed by filling a second part (85 b of FIG. 17)of the trench 85. The second metal gate electrode 220 does not includethe p-type work function adjusting layer 122.

The first lower metal gate electrode 124 and the second lower metal gateelectrode 224 are separated from each other by the p-type work functionadjusting layer 122, and the first upper metal gate electrode 126 andthe second upper metal gate electrode 226 are also separated from eachother.

The p-type work function adjusting layer 122 may include a first part122 a, a second part 122 b and a third part, which are connected to oneanother. The first part 122 a of the p-type work function adjustinglayer 122 may be formed along the bottom surface of the trench 85, thatis, along the substrate 10 and the first gate dielectric layer 110, thethird part of the p-type work function adjusting layer 122 may be formedalong sidewalls of the trench 85, and the second part 122 b of thep-type work function adjusting layer 122 extending in a normal directionof the substrate 10 may be formed on the field region 40. That is, thesecond part 122 b of the p-type work function adjusting layer 122 is notformed along the sidewalls and bottom surface of the trench 85 andprotrudes from a given portion MI of the bottom surface of the trench 85overlapping with the field region 40. The second part 122 b of thep-type work function adjusting layer 122 protrudes in the normaldirection of the substrate 10 between the first active region 20 and thesecond active region 30.

The first lower metal gate electrode 124 and the second lower metal gateelectrode 224 are separated from each other by the second part 122 b ofthe p-type work function adjusting layer 122. That is, the second part122 b of the p-type work function adjusting layer 122 is interposedbetween the first lower metal gate electrode 124 and the second lowermetal gate electrode 224. Likewise, the first upper metal gate electrode126 and the second upper metal gate electrode 226 are separated fromeach other by the second part 122 b of the p-type work functionadjusting layer 122. Although the first lower metal gate electrode 124and the second lower metal gate electrode 224 are separated from eachother by the p-type work function adjusting layer 122, because thep-type work function adjusting layer 122 includes a conductive material,the first lower metal gate electrode 124 and the second lower metal gateelectrode 224 are electrically connected to each other.

In the semiconductor device 3 according to the third exemplaryembodiment, the contact surface MI between the first metal gateelectrode 120 and the second metal gate electrode 220 is defined by thesecond part 122 b of the p-type work function adjusting layer 122.

The first lower metal gate electrode 124 may be formed along the p-typework function adjusting layer 122, and the first upper metal gateelectrode 126 may be formed by filling a space defined by the firstlower metal gate electrode 124. The second lower metal gate electrode224 may be formed along the sidewalls and bottom surface of the trench85 and the second part 122 b of the p-type work function adjusting layer122, and the second upper metal gate electrode 226 may be formed byfilling a space defined by the second lower metal gate electrode 224.

The semiconductor device 4 according to the fourth exemplary embodimentwill now be described with reference to FIGS. 1 and 5. The followingdescription will focus on differences between the first and fifthexemplary embodiments in accordance with principles of inventiveconcepts.

FIG. 5 is a cross-sectional view illustrating the semiconductor deviceaccording to the fifth exemplary embodiment, taken along lines A-A, B-Band C-C of FIG. 1.

Referring to FIG. 5, the gate dielectric layers 110 and 210 are formedalong the sidewalls and bottom surface of the trench 85. That is, thefirst gate dielectric layer 110 formed between the substrate 10 and thefirst metal gate electrode 120 and the second gate dielectric layer 210formed between the substrate 10 and the second metal gate electrode 220are formed along the sidewalls and bottom surface of the trench 85.

The p-type work function adjusting layer 122 is generally formed alongthe sidewalls and bottom surface of the trench 85, that is, along thefirst gate dielectric layer 110, and extends in the normal direction ofthe substrate 10 while not including a portion formed on the fieldregion 40. Therefore, the first lower metal gate electrode 124 and thesecond lower metal gate electrode 224 are formed along the sidewalls andbottom surface of the trench 85 to then be directly connected to eachother.

The first upper metal gate electrode 126 and the second upper metal gateelectrode 226 are formed by filling the trench 85 to then be directlyconnected to each other.

Next, a semiconductor device according to a fifth exemplary embodimentwill be described with reference to FIGS. 6 and 7.

FIG. 6 is a perspective view illustrating semiconductor devicesaccording to fifth and sixth exemplary embodiments in accordance withprinciples of inventive concepts, and FIG. 7 is a cross-sectional viewillustrating the semiconductor device according to the fifth exemplaryembodiment, taken along lines D-D, E-E and F-F of FIG. 6. For brevityand clarity of explanation, an interlayer dielectric layer 80 is notillustrated in FIG. 6.

The first fin type active pattern 60 and the second fin type activepattern 70 shown in FIG. 6 correspond to the first active region and thesecond active region 30 shown in FIG. 1, and explanations thereof willnot be repeated in detail here.

Referring to FIGS. 6 and 7, the semiconductor device according to thefifth exemplary embodiment may include a substrate 10, a first fin typeactive pattern 60, a second fin type active pattern 70, a gate structure50, a first elevated source/drain 135, a second elevated source/drain235 and an interlayer dielectric layer 80.

The first fin type active pattern 60 and the second fin type activepattern 70 are adjacent to each other, in the sense that, although fieldregion 40 lies between them (and they are, therefore, not adjacent inthat sense), no active pattern lies between them, and may extend inparallel lengthwise in the second direction DR2. The first fin typeactive pattern 60 and the second fin type active pattern 70 may beportions of the substrate 10 and may include an epitaxial layer grownfrom the substrate 10.

In exemplary embodiments in accordance with principles of inventiveconcepts, first fin type active pattern 60 is a PMOS forming region andthe second fin type active pattern 70 is an NMOS forming region. Whenthe first fin type active pattern 60 and the second fin type activepattern 70 include the epitaxial layer grown from the substrate 10, thefirst fin type active pattern 60 and the second fin type active pattern70 may include a single element semiconductor, such as silicon orgermanium. Alternatively, the first fin type active pattern 60 and thesecond fin type active pattern 70 may include a compound semiconductor,for example, a group IV-IV compound semiconductor or a group III-Vcompound semiconductor. In exemplary embodiments in accordance withprinciples of inventive concepts, the group IV-IV compound semiconductormay be, for example, a binary compound or a ternary compound includingat least two elements of carbon (C), silicon (Si), germanium (Ge), andtin (Sn) or a compound doped with a IV group element. The group III-Vcompound semiconductor may include, for example, a binary compound, aternary compound or a quaternary compound, prepared by combining atleast one group III element of aluminum (Al), gallium (Ga) and indium(In) with at least one group V element of phosphorus (P), arsenic (As)and antimony (Sb).

The field region 40 may be formed between the first fin type activepattern 60 and the second fin type active pattern 70 while making directcontact with the first fin type active pattern 60 and the second fintype active pattern 70. Additionally, the field region 40 may be formedin contact with portions of the first fin type active pattern 60 and thesecond fin type active pattern 70. That is, the first fin type activepattern 60 and the second fin type active pattern 70 may protrude fromthe field region 40. Because the field region 40 electricallydisconnects a device formed on the first fin type active pattern 60 froma device formed on the second fin type active pattern 70, it may be anisolation layer.

The gate structure 50 may be formed to intersect the first fin typeactive pattern 60, the field region 40 and the second fin type activepattern 70. The gate structure 50 may extend in the first direction DR1.In exemplary embodiments in accordance with principles of inventiveconcepts, gate structure 50 includes a first metal gate electrode 120 asa p-type metal gate electrode formed on the first fin type activepattern 60, and a second metal gate electrode 220 as an n-type metalgate electrode formed on the second fin type active pattern 70. Thefirst metal gate electrode 120 and the second metal gate electrode 220directly contact each other.

A p type FINFET 10 p may be formed at an intersection of the first fintype active pattern 60 and the gate structure 50, and an n type FINFET10 n may be formed at an intersection of the second fin type activepattern 70 and the gate structure 50.

In exemplary embodiments in accordance with principles of inventiveconcepts, first metal gate electrode 120 includes a p-type work functionadjusting layer 122 and a first lower metal gate electrode 124sequentially formed along the first fin type active pattern 60protruding from the field region 40, and a first upper metal gateelectrode 126 filling a portion of a trench 85. The second metal gateelectrode 220 includes a second lower metal gate electrode 224 formedalong the first fin type active pattern 60 protruding from the fieldregion 40 and a second upper metal gate electrode 226 filling the restportion of the trench 85. However, in exemplary embodiments, the secondmetal gate electrode 220 does not include the p-type work functionadjusting layer 122.

The first lower metal gate electrode 124 formed along the first fin typeactive pattern 60 and the second lower metal gate electrode 224 formedalong the second fin type active pattern 70 extend onto the field region40 to then be directly connected to each other. In addition, the firstupper metal gate electrode 126 and the second upper metal gate electrode226 are also directly connected to each other.

The contact surface MI between the first metal gate electrode 120 andthe second metal gate electrode 220 may be defined by the p-type workfunction adjusting layer 122 of the first metal gate electrode 120. Anoverlapping width of the p-type work function adjusting layer 122 andthe field region 40 is a first width W1 and a non-overlapping width ofthe p-type work function adjusting layer 122 and the field region 40 isa second width W2, which is greater than the first width W1. Therefore,the contact surface MI between the first metal gate electrode 120 andthe second metal gate electrode 220 is positioned closer to the firstfin type active pattern 60 than to the second fin type active pattern70.

That is, the overlapping width W1 of the first metal gate electrode 120and the field region 40 is smaller than the overlapping width W2 of thesecond metal gate electrode 220 and the field region 40. Therefore, thefirst metal gate electrode 120 does not overlap with the center line CLof the field region 40 equidistantly spaced apart from the first fintype active pattern 60 and the second fin type active pattern 70.

The first gate dielectric layer 110 and the second gate dielectric layer210 may be formed between the gate structure 50 and the first fin typeactive pattern 60 and between the gate structure 50 and the second fintype active pattern 70. The first gate dielectric layer 110 and thesecond gate dielectric layer 210 may be defined by the contact surfaceMI and may be formed on the field region 40 between the first fin typeactive pattern 60 and the second fin type active pattern 70. The firstgate dielectric layer 110 and the second gate dielectric layer 210 mayinclude a high-k dielectric layer.

The first elevated source/drain 135 may be formed on the first fin typeactive pattern 60 at both sides of the gate structure 50. Because a PMOStransistor is formed on the first fin type active pattern 60, the firstelevated source/drain 135 may include a compressive stress material. Forexample, when the first fin type active pattern 60 includes silicon, thecompressive stress material may be a material having a greater latticeconstant than silicon (Si), e.g., SiGe.

The second elevated source/drain 235 may be formed on the second fintype active pattern 70 at both sides of the gate structure 50. Becausean NMOS transistor is formed on the first fin type active pattern 60,the second elevated source/drain 235 may include the same material asthe second fin type active pattern 70, or a tensile stress material. Forexample, when the second fin type active pattern 70 includes silicon,the second elevated source/drain 235 may be silicon or a material havinga smaller lattice constant than silicon (Si), e.g., SiC.

The first elevated source/drain 135 and the second elevated source/drain235 may have various shapes. For example, the first elevatedsource/drain 135 and the second elevated source/drain 235 may have theshape of a diamond, a circle, or a rectangle. In FIG. 6, the firstelevated source/drain 135 and the second elevated source/drain 235shaped are of a diamond (or a pentagon or a hexagon) shape.

Hereinafter, the semiconductor device according to the sixth exemplaryembodiment in accordance with principles of inventive concepts will bedescribed with reference to FIGS. 6 and 8. The following descriptionwill focus on differences between the fifth and sixth exemplaryembodiments.

FIG. 8 is a cross-sectional view illustrating the semiconductor deviceaccording to the sixth exemplary embodiment, taken along lines D-D, E-Eand F-F of FIG. 6.

Referring to FIG. 8, the semiconductor device 6 according to the sixthexemplary embodiment further includes a channel layer 115 formed betweena first fin type active pattern 60 and a first metal gate electrode 120.

The channel layer 115 may include a different material from a materialfor forming the first fin type active pattern 60. When the first fintype active pattern 60 is a silicon element semiconductor, the channellayer 115 may include a material having a greater lattice constant thansilicon (Si). For example, the channel layer 115 may include silicongermanium (SiGe) having a greater lattice constant than silicon (Si).That is, in exemplary embodiments in accordance with principles ofinventive concepts, the channel layer 115 may be a silicon germaniumchannel layer.

The channel layer 115 may be formed along at least a portion of thefirst fin type active pattern 60. For example, the channel layer 115 maybe formed along the first fin type active pattern 60 protruding from thefield region 40 and may extend only to the field region 40.

Hereinafter, a semiconductor device according to a seventh exemplaryembodiment in accordance with principles of inventive concepts will bedescribed with reference to FIGS. 9 and 10. The following descriptionwill focus on differences between the fifth and seventh exemplaryembodiments.

FIG. 9 is a perspective view illustrating a semiconductor deviceaccording to a seventh exemplary embodiment and FIG. 10 is across-sectional view illustrating the semiconductor device according tothe seventh exemplary embodiment, taken along lines D-D, E-E and F-F ofFIG. 9. For clarity and brevity of description, interlayer dielectriclayer 80 is not illustrated in FIG. 9.

Referring to FIGS. 9 and 10, the first lower metal gate electrode 124and the second lower metal gate electrode 224 are spatially separatedfrom each other by the p-type work function adjusting layer 122. Thatis, a portion of the p-type work function adjusting layer 122 intervenesbetween the first lower metal gate electrode 124 and the second lowermetal gate electrode 224.

The p-type work function adjusting layer 122 may be formed alongportions of the first fin type active pattern 60 and the field region40. The width of the p-type work function adjusting layer 122 extendingonto the field region 40 is a first width W1. At a portion spaced thefirst width W1 apart from the first fin type active pattern 60, thep-type work function adjusting layer 122 includes a portion extending ina direction in which the first fin type active pattern 60 protrudes.That is to say, the p-type work function adjusting layer 122 includes aportion protruding from the field region 40 between the first fin typeactive pattern 60 and the second fin type active pattern 70. The firstlower metal gate electrode 124 and the second lower metal gate electrode224 are separated from each other by the protruding portion.

The p-type work function adjusting layer 122 becomes an isolation filmbetween the first lower metal gate electrode 124 and the second lowermetal gate electrode 224. Because the p-type work function adjustinglayer 122 includes a conductive material, the first lower metal gateelectrode 124 and the second lower metal gate electrode 224 areelectrically connected to each other.

FIGS. 11 and 12 are a circuit view and a layout view illustrating asemiconductor device according to an eighth exemplary embodiment inaccordance with principles of inventive concepts.

Referring to FIGS. 11 and 12, the semiconductor device 8 according to aneighth exemplary embodiment may include a pair of inverters INV1 andINV2 connected in parallel between a power supply node Vcc and a groundnode Vss, and a first pass transistor PS1 and a second pass transistorPS2 connected to output nodes of the inverters INV1 and INV2. The firstpass transistor PS1 and the second pass transistor PS2 may be connectedto a bit line BL and a complementary bit line BLb. Gates of the firstpass transistor PS1 and the second pass transistor PS2 may be connectedto a word line WL.

In exemplary embodiments in accordance with principles of inventiveconcepts, first inverter INV1 includes a first pull-up transistor PU1and a first pull-down transistor PD1 connected in series to each other,and the second inverter INV2 includes a second pull-up transistor PU2and a second pull-down transistor PD2 connected in series to each other.The first pull-up transistor PU1 and the second pull-up transistor PU2may be PMOS transistors, and the first pull-down transistor PD1 and thesecond pull-down transistor PD2 may be NMOS transistors, for example.

In order to constitute a latch circuit, an input node of the firstinverter INV1 may be connected to an output node of the second inverterINV2 and an input node of the second inverter INV2 may be connected toan output node of the first inverter INV1.

Referring to FIGS. 11 and 12, a third active region 310, a fourth activeregion 320, a fifth active region 330 and a sixth active region 340,which are spaced apart from one another, may extend lengthwise in adirection (e.g., in an up-and-down direction of FIG. 12). The fourthactive region 320 and the fifth active region 310 may extend in smallerlengths than the third active region 310 and the sixth active region340.

In addition, a first gate electrode 351, a second gate electrode 352, athird gate electrode 353, and a fourth gate electrode 354 are formed toextend in another direction (for example, in a left-and-right directionof FIG. 12) to intersect the third active region 310 to the sixth activeregion 340. In exemplary embodiments in accordance with principles ofinventive concepts, the first gate electrode 351 completely intersectsthe third active region 310 and the fourth active region 320 (that is,first gate electrode 351 extends in full width completely across thirdand fourth active regions 310, 320) while partially overlapping with aterminal of the fifth active region 330. The third gate electrode 353completely intersects the sixth active region 340 and the fifth activeregion 330 (that is, third gate electrode 353 extends in full widthcompletely across fifth and sixth active regions 330, 340) whilepartially overlapping with a terminal of the fourth active region 320.The second gate electrode 352 and the fourth gate electrode 354 areformed to intersect the third active region 310 and the sixth activeregion 340, respectively.

In exemplary embodiments in accordance with principles of inventiveconcepts, the first pull-up transistor PU1 is defined in vicinity of anintersection of the first gate electrode 351 and the fourth activeregion 320, the first pull-down transistor PD1 is defined in vicinity ofan intersection of the first gate electrode 351 and the third activeregion 310, and the first pass transistor PS1 is defined in vicinity ofan intersection of the second gate electrode 352 and the third activeregion 310. The second pull-up transistor PU2 is defined in vicinity ofan intersection of the third gate electrode 353 and the fifth activeregion 330, the second pull-down transistor PD2 is defined in vicinityof an intersection of the third gate electrode 353 and the sixth activeregion 340, and the second pass transistor PS2 is defined in vicinity ofan intersection of the fourth gate electrode 354 and the sixth activeregion 340.

Although not specifically shown, sources/drains may be formed atopposite sides of the respective intersections of the first to fourthgate electrodes 351-354 and the third to sixth active regions 310, 320,330 and 340.

In addition, a plurality of contacts 350 may be formed.

Additionally, a shared contact 361 concurrently connects the fourthactive region 320, a third gate line 353 and a wire 371. A sharedcontact 362 may also concurrently connect the fifth active region 330, afirst gate line 351 and a wire 372.

In exemplary embodiments in accordance with principles of inventiveconcepts, the first gate electrode 351 and the third gate electrode 353may correspond to the gate structure 50 shown in FIGS. 1 to 10, thefourth active region 320 and the fifth active region 330 may correspondto the first active region 20 and the first fin type active pattern 60shown in FIGS. 1 to 10, and the third active region 310 and the sixthactive region 340 may correspond to the second active region 30 and thesecond fin type active pattern 70 shown in FIGS. 1 to 10.

FIG. 13 is a block diagram of an electronic system including asemiconductor device in accordance with principles of inventiveconcepts.

Electronic system 1100 may include a controller 1110, an input/outputdevice (I/O) 1120, a memory 1130, an interface 1140 and a bus 1150. Thecontroller 1110, the I/O 1120, the memory 1130, and/or the interface1140 may be connected to each other through the bus 1150. The bus 1150corresponds to a path through which data moves.

The controller 1110 may include at least one of a microprocessor, adigital signal processor, a microcontroller, and logic elements capableof functions similar to those of these elements. The I/O 1120 mayinclude a keypad, a keyboard, a display device, and so on. The memory1130 may store data and/or commands. The interface 1140 may performfunctions of transmitting data to a communication network or receivingdata from the communication network. The interface 1140 may be wired orwireless. For example, the interface 1140 may include an antenna or awired/wireless transceiver, and so on. Although not shown, theelectronic system 1100 may further include high-speed DRAM and/or SRAMas working memory for improving the operation of the controller 1110. Asemiconductor device in accordance with principles of inventive conceptsmay be provided in the memory 1130 or may be provided some components ofthe controller 1110 or the I/O 1120, for example.

The electronic system 1100 may be applied to a portable electronicdevice, such as a personal digital assistant (PDA), a portable computer,a web tablet, a wireless phone, a mobile phone, a digital music player,a memory card, or any type of electronic device capable of transmittingand/or receiving information in a wireless environment.

FIGS. 14 and 15 illustrate an exemplary semiconductor system to which asemiconductor device in accordance with principles of inventive conceptscan be employed. FIG. 14 illustrates an example in which a semiconductordevice in accordance with principles of inventive concepts is applied toa tablet PC, and FIG. 15 illustrates an example in which a semiconductordevice in accordance with principles of inventive concepts is applied toa notebook computer. Semiconductor devices in accordance with principlesof inventive concepts may also be applied to other IC devices notillustrated herein.

Hereinafter, a method for fabricating the semiconductor device accordingto the third exemplary embodiment in accordance with principles ofinventive concepts will be described with reference to FIGS. 1, 4 and 16to 21.

FIGS. 16 to 21 illustrate intermediate process steps in a method forfabricating the semiconductor device according to the third exemplaryembodiment in accordance with principles of inventive concepts.

Referring to FIGS. 1 and 16, a substrate 10 is provided, the substrate10 including a first active region 20, a second active region 30, and afield region 40. The field region 40 is positioned between the firstactive region 20 and the second active region 30 while making directcontact with the first active region 20 and the second active region 30.The field region 40 has a center line CL equidistantly spaced apart fromthe first active region 20 and the second active region 30.

The field region 40 may be formed as a shallow trench isolation (STI),but aspects of inventive concepts are not limited thereto.

Because, in this exemplary embodiment, the first active region 20 is aPMOS forming region and the second active region 30 is an NMOS formingregion, n-type impurity and p-type impurity may be doped into the firstactive region 20 and the second active region 30, respectively, toimplement PMOS and NMOS.

A pre-gate dielectric layer 110 p and the dummy gate structures 114 and214 intersecting the first active region 20, the field region 40 and thesecond active region 30 are formed on the substrate 10. Because thepre-gate dielectric layer 110 p and the dummy gate structures 114 and214 are formed by the same patterning process, the pre-gate dielectriclayer 110 p is formed along a top surface of the substrate 10.

The dummy gate structures 114 and 214 include a first dummy gateelectrode 114 intersecting the first active region 20, and a seconddummy gate electrode 214 intersecting the second active region 30.

The pre-gate dielectric layer 110 p may include, for example, one of asilicon oxide (SiO₂) layer, a silicon oxynitride (SiON) layer and acombination thereof, or a high-k dielectric layer, for example. Themethod for fabricating the semiconductor device according to the thirdexemplary embodiment will be described with regard to a case in whichthe pre-gate dielectric layer 110 p includes a high-k dielectric layer.

The dummy gate structures 114 and 214 may include, for example, silicon.In exemplary embodiments in accordance with principles of inventiveconcepts, the dummy gate structures 114 and 214 may include one ofpolycrystalline silicon (poly Si), amorphous silicon (a-Si) and acombination thereof. The first dummy gate electrode 117 may be undopedor may be doped with a similar impurity.

After forming the pre-gate dielectric layer 110 p and the dummy gatestructures 114 and 214, a first source/drain 130 may be formed at bothsides of the first dummy gate electrode 114, and a second source/drain230 may be formed at both sides of the second dummy gate electrode 214.

Next, an interlayer dielectric layer 80 may be formed on the substrate10, the interlayer dielectric layer 80 covering the dummy gatestructures 114 and 214, the first active region 20, the field region 40and the second active region 30. The interlayer dielectric layer 80 mayinclude, for example, at least one of a low-k material layer, an oxidelayer, a nitride layer, and an oxynitride layer.

Next, the interlayer dielectric layer 80 may be planarized to expose topsurfaces of the dummy gate structures 114 and 214. In the planarizing, achemical mechanical polishing (CMP) process may be used, for example.

Referring to FIG. 17, a first part 85 a of the trench 85 intersecting aportion of the field region 40 and the first active region 20 may beformed in the interlayer dielectric layer 80 by removing the first dummygate electrode 114. The field region 40 and the first active region 20are not exposed by the first part 85 a of the trench 85.

The first part 85 a of the trench 85 is part of the trench 85intersecting the field region 40 and the second active region 30, thatis, the part overlapping the portion of the field region 40 and thefirst active region 20.

One of sidewalls of the first part 85 a of the trench 85 corresponds tothe second dummy gate electrode 214.

A width of the first part 85 a of the trench 85 overlapping with thefield region 40 corresponds to the first width W1. Therefore, anoverlapping width between the second dummy gate electrode 214 and thefield region 40 corresponds to the second width W2. The sum of the firstwidth W1 and the second width W2 is equal to a width W of the fieldregion 40.

Because the width W1 of the first part 85 a of the trench 85 overlappingwith the field region 40 is smaller than the width W1 of the seconddummy gate electrode 214 overlapping with the field region 40, the firstpart 85 a of the trench 85 may not overlap with, that is, may not reach,the center line CL of the field region 40.

The first dummy gate electrode 114 may be removed by etching, forexample, by dry etching.

Referring to FIG. 18, a conductive layer 122 p may be formed along a topsurface of the interlayer dielectric layer 80, sidewalls and a bottomsurface of the first part 85 a of the trench 85 and a top surface of thesecond dummy gate electrode 214. That is, the conductive layer 122 pcovers the first active region 20, the second active region 30 and thefield region 40.

The conductive layer 122 p may include at least one of a TiN layer and aTaN layer, and may be formed by, for example, chemical vapor deposition(CVD) or atomic layer deposition (ALD), for example.

Next, a sacrificial layer 123 may be formed to fill the first part 85 aof the trench 85 having the conductive layer 122 p. The sacrificiallayer 123 may also be formed on the interlayer dielectric layer 80 andthe second dummy gate electrode 214 while filling the first part 85 a ofthe trench 85. The sacrificial layer 123 may include a material havinggood gap-fill capability.

Referring to FIG. 19, the sacrificial layer 123 and the conductive layer122 p are planarized to expose a top surface of the interlayerdielectric layer 80 and a top surface of the second dummy gate electrode214. As the result, a p-type work function adjusting layer 122 may beformed along the sidewalls and bottom surface of the first part 85 a ofthe trench 85.

The p-type work function adjusting layer 122 may be formed by removing aportion of the field region 40, the portion having the second width W2and a portion of the conductive layer 122 p overlapping with the secondactive region 30.

The p-type work function adjusting layer 122 formed on the pre-gatedielectric layer 110 p extends onto the field region 40 whileintersecting the first active region 20. An overlapping width betweenthe p-type work function adjusting layer 122 and the field region 40 isequal to the first width W1 of the first part 85 a of the trench 85overlapping with the field region 40. Therefore, the p-type workfunction adjusting layer 122 may not overlap with, that is, may notreach, the center line CL of the field region 40.

After forming the p-type work function adjusting layer 122, the restportion of the sacrificial layer 123 filling the first part 85 a of thetrench 85 may be removed.

Referring to FIG. 20, the second part 85 b of the trench 85 positionedin vicinity of the first part 85 a of the trench 85 may be formed in theinterlayer dielectric layer 80 by removing the second dummy gateelectrode 214. The second part 85 b of the trench 85 intersects theremaining portion of the field region 40 not overlapping with the p-typework function adjusting layer 122 and the second active region 30. Thefield region 40 and the second active region 30 are not exposed by thesecond part 85 b of the trench 85.

One of sidewalls of the second part 85 b of the trench 85 corresponds tothe second part 122 b of the p-type work function adjusting layer 122.The second part 122 b of the p-type work function adjusting layer 122protrudes in a direction normal to the substrate 10, between the firstactive region 20 and the second active region 30.

The width of the second part 85 b of the trench 85 overlapping with thefield region 40 corresponds to the second width W2 of the second dummygate electrode 214 overlapping with the field region 40.

The second dummy gate electrode 214 may be removed by etching, forexample, dry etching or wet etching.

Referring to FIG. 21, a first electrode layer 124 p may be formed alongthe top surface of the interlayer dielectric layer 80, the top surfaceof the p-type work function adjusting layer 122 and the sidewalls andbottom surface of the second part 85 b of the trench 85.

After forming the first electrode layer 124 p, a second electrode layer126 p may be formed on the first electrode layer 124 p, the secondelectrode layer 126 p filling the first part 85 a of the trench 85 andthe second part 85 b of the trench 85. The second electrode layer 126 pmay also be formed along the top surface of the interlayer dielectriclayer 80 while filling the first part 85 a of the trench 85 and thesecond part 85 b of the trench 85.

The first electrode layer 124 p may include, for example, at least oneof TiN, TaN, TaC, TaCN, TiAl, and TiAlC, and the second electrode layer126 p may include, for example, at least one of Al and W.

Referring to FIG. 4, the first electrode layer 124 p and the secondelectrode layer 126 p are planarized to expose the top surface of theinterlayer dielectric layer 80. As the result, a gate structure 50 isformed, the gate structure 50 intersecting the first active region 20,the second active region 30 and the field region 40.

In this exemplary embodiment, gate structure 50 includes a first metalgate electrode 120 and a second metal gate electrode 220 directlycontacting each other. The gate structure 50 includes a contact surfaceMI between the first metal gate electrode 120 and the second metal gateelectrode 220. The contact surface MI may be defined by the p-type workfunction adjusting layer 122.

In addition, the first metal gate electrode 120 may not overlap with,that is, may not reach, the center line CL of the field region 40.Therefore, the contact surface MI between the first metal gate electrode120 and the second metal gate electrode 220 is positioned closer to thefirst active region 20 than to the second active region 30.

Hereinafter, a method for fabricating the semiconductor device accordingto the fourth exemplary embodiment in accordance with principles ofinventive concepts will be described with reference to FIGS. 1, 5, 16and 22 to 25.

FIGS. 22 to 25 illustrate intermediate process steps in a method forfabricating the semiconductor device according to the fourth exemplaryembodiment in accordance with principles of inventive concepts.

Referring to FIGS. 16 and 22, a trench 85 may be formed in theinterlayer dielectric layer 80 by removing the pre-gate dielectric layer110 p and the dummy gate structures 114 and 214 intersecting the firstactive region 20, the second active region 30 and the field region 40.

The method for fabricating the semiconductor device according to thefourth exemplary embodiment in accordance with principles of inventiveconcepts will be described with regard to a case where the pre-gatedielectric layer 110 p is a dummy gate dielectric layer.

The trench 85 intersects the first active region 20, the second activeregion 30 and the field region 40 and exposes the first active region 20and the second active region 30.

Referring to FIG. 23, a dielectric layer 111 and a conductive layer 122p are sequentially formed along a top surface of the interlayerdielectric layer 80 and sidewalls and bottom surface of the trench 85.

The dielectric layer 111 and the conductive layer 122 p cover the firstactive region 20, the second active region 30 and the field region 40.

The dielectric layer 111 may include a high-k material, and theconductive layer 122 p may include a material capable of controlling awork function of a pMOS.

Referring to FIG. 24, a pre p-type work function adjusting layer 121 maybe formed on the field region 40 and the first active region 20 byremoving a portion of the conductive layer 122 p. The pre p-type workfunction adjusting layer 121 may overlap with the field region 40 andthe first active region 20.

The width of the pre p-type work function adjusting layer 121overlapping with the field region 40 is a first width W1. The pre p-typework function adjusting layer 121 may not overlap with, that is, may notreach, center line CL of the field region 40.

The portion of the conductive layer 122 p may be removed by, forexample, wet etching or dry etching.

Referring to FIG. 25, a first conductive layer 122 p may be formed alonga top surface of the interlayer dielectric layer 80 and sidewalls andbottom surface of the trench 85.

Next, a second conductive layer 122 p filling the trench 85 may beformed on the first conductive layer 122 p. The second conductive layer122 p is also formed on the top surface of the interlayer dielectriclayer 80.

Referring back to FIG. 5, the dielectric layer 111 formed on the topsurface of the interlayer dielectric layer 80, the pre p-type workfunction adjusting layer 121, the first electrode layer 124 p and thesecond electrode layer 126 p are removed by a planarization process. Asthe result, the gate structure 50 intersecting the first active region20, the second active region 30 and the field region 40 is formed.

Hereinafter, a method for fabricating the semiconductor device accordingto the fifth exemplary embodiment in accordance with principles ofinventive concepts will be described with reference to FIGS. 6, 7 and262 to 30.

FIGS. 26 to 30 illustrate intermediate process steps in a method forfabricating the semiconductor device according to the fifth exemplaryembodiment in accordance with principles of inventive concepts.

Referring to FIG. 26, the first fin type active pattern 60 and thesecond fin type active pattern 70 adjacent to each other are formed onthe substrate 10.

Field region 40 may be formed between the first fin type active pattern60 and the second fin type active pattern 70 while making direct contactwith the first fin type active pattern 60 and the second fin type activepattern 70. The field region 40 may be formed in contact with portionsof the first fin type active pattern 60 and the second fin type activepattern 70. The field region 40 includes the center line CLequidistantly spaced apart from the first active region 20 and thesecond active region 30.

The first fin type active pattern 60 is a p-type FINFET forming regionand the second fin type active pattern 70 is an n-type FINFET formingregion.

Next, the dummy gate dielectric layers 112 and 212 and the dummy gatestructures 114 and 214 intersecting the first fin type active pattern60, the field region 40 and the second fin type active pattern 70 areformed on the substrate 10.

The dummy gate structures 114 and 214 include a first dummy gateelectrode 114 intersecting the first fin type active pattern 60 and asecond dummy gate electrode 214 intersecting the second fin type activepattern 70. In addition, the dummy gate dielectric layers 112 and 212include a first dummy gate dielectric layer 112 formed between the firstfin type active pattern 60 and the first dummy gate electrode 114 and asecond dummy gate dielectric layer 212 formed between the second fintype active pattern 70 and the second dummy gate electrode 214.

The dummy gate dielectric layers 112 and 212 may include silicon oxideand the dummy gate structures 114 and 214 include one of polycrystallinesilicon (poly Si), amorphous silicon (a-Si) and a combination thereof.

Next, the first fin type active pattern 60 and the second fin typeactive pattern 70 exposed at both sides of the dummy gate structures 114and 214 are recessed. The first elevated source/drain 135 and the secondelevated source/drain 235 are formed on the recessed first and secondfin type active patterns 60 and 70, respectively.

Next, the interlayer dielectric layer 80 covering the dummy gatestructures 114 and 214, the first elevated source/drain 135 and thesecond elevated source/drain 235 may be formed on the substrate 10.

Next, the interlayer dielectric layer 80 may be planarized to expose topsurfaces of the dummy gate structures 114 and 214.

Referring to FIG. 27, the dummy gate structures 114 and 214 and thedummy gate dielectric layers 112 and 214 are sequentially removed,thereby forming the trench 85 exposing the first fin type active pattern60, the field region 40 and the second fin type active pattern 70 in theinterlayer dielectric layer 80.

The first fin type active pattern 60 and the second fin type activepattern 70 are exposed by the trench 85.

Referring to FIG. 28, the dielectric layer 111 and the conductive layer122 p covering the first fin type active pattern 60, the field region 40and the second fin type active pattern 70 are sequentially formed.

The dielectric layer 111 and the conductive layer 122 p are formed alongthe top surface of the interlayer dielectric layer 80, the sidewalls andbottom surface of the trench 85, and the first fin type active pattern60 and the second fin type active pattern 70 protruding from the fieldregion 40.

Referring to FIG. 29, the pre p-type work function adjusting layer 121may be formed on the field region 40 and the first fin type activepattern 60 by removing a portion of the conductive layer 122 p.

The pre p-type work function adjusting layer 121 overlaps with the fieldregion 40 and the first fin type active pattern 60 while not overlappingwith the center line of the field region 40. The width of the pre p-typework function adjusting layer 121 overlapping with the field region 40corresponds to the first width W1.

Referring to FIG. 30, the first conductive layer 122 p may be formedalong the top surface of the interlayer dielectric layer 80, thesidewalls and bottom surface of the trench 85, and the first fin typeactive pattern 60 and the second fin type active pattern 70 protrudingfrom the field region 40.

Next, the second conductive layer 122 p filling the trench 85 may beformed on the first conductive layer 122 p. The second conductive layer122 p is also formed on the interlayer dielectric layer 80.

Referring back to FIG. 7, the dielectric layer 111 formed on the topsurface of the interlayer dielectric layer 80, the pre p-type workfunction adjusting layer 121, the first electrode layer 124 p and thesecond electrode layer 126 p are removed by a planarization process. Asa result, the gate structure 50 may be formed, the gate structure 50intersecting the first fin type active pattern 60, the second fin typeactive pattern 70 and the field region 40.

While exemplary embodiments of inventive concepts has been particularlyshown and described with reference to exemplary embodiments thereof, itwill be understood by those of ordinary skill in the art that variouschanges in form and details may be made therein without departing fromthe spirit and scope of inventive concepts as defined by the followingclaims. It is therefore desired that the present embodiments beconsidered in all respects as illustrative and not restrictive,reference being made to the appended claims rather than the foregoingdescription to indicate the scope of inventive concepts.

1. A semiconductor device comprising: a substrate including a firstactive region, a second active region and a field region, the fieldregion being disposed between the first active region and the secondactive region, the field region directly contacting both the firstactive region and the second active region; an interlayer dielectriclayer disposed on or above the substrate and including a trench; a gatedielectric layer disposed in the trench and including a high-k material,the gate dielectric layer including a first side portion formed on afirst sidewall of the trench, a second side portion formed on a secondsidewall of the trench and a bottom portion formed on a bottom surfaceof the trench; a first metal gate electrode disposed on or above thefirst active region, and disposed on or above the gate dielectric layer;and a second metal gate electrode disposed on or above the second activeregion, and disposed on or above the gate dielectric layer, wherein thefirst metal gate electrode directly contacts the second metal gateelectrode, a contact surface between the first metal gate electrode andthe second metal gate electrode is closer to the first active regionthan to the second active region, the contact surface being disposed onor above the field region, a depth of the second metal gate electrode isgreater than a depth of the first metal gate electrode, and theinterlayer dielectric layer does not directly contact the first metalgate electrode and the second metal gate electrode.
 2. The semiconductordevice of claim 1, further comprising a work function layer on which thefirst metal gate electrode is disposed.
 3. The semiconductor device ofclaim 1, wherein the first active region is a PMOS forming region, andthe second active region is an NMOS forming region.
 4. The semiconductordevice of claim 1, wherein the first metal gate electrode and the secondmetal gate electrode are formed with the same material.
 5. Thesemiconductor device of claim 1, wherein a width of a first metal gateelectrode is less than a width of the second metal gate electrode. 6.The semiconductor device of claim 1, wherein a shortest distance betweenthe substrate and the first metal gate electrode is greater than ashortest distance between the substrate and the second metal gateelectrode.
 7. The semiconductor device of claim 1, wherein the depth ofthe second metal gate electrode that is disposed on or above the fieldregion is greater than the depth of the first metal gate electrode thatis disposed on or above the field region.
 8. The semiconductor device ofclaim 1, wherein the first metal gate electrode includes a first uppermetal gate electrode and a first lower metal gate electrode, the secondmetal gate electrode includes a second upper metal gate electrode and asecond lower metal gate electrode, the first upper metal gate electrodeand the second upper metal gate electrode are formed with the samematerial, and the first lower metal gate electrode and the second lowermetal gate electrode are formed with the same material.
 9. Thesemiconductor device of claim 1, wherein a top surface of the firstmetal gate electrode, a top surface of the second metal gate electrodeand a top surface of the interlayer dielectric layer are coplanar witheach other.
 10. The semiconductor device of claim 1, further comprisinga spacer disposed between the second metal gate electrode and theinterlayer dielectric layer, wherein a height of the spacer issubstantially the same as a distance between a top surface of the secondmetal gate electrode and a bottom surface of the bottom portion of thegate dielectric layer.
 11. The semiconductor device of claim 10, whereinthe interlayer dielectric layer is disposed on a sidewall of the spacerand does not entirely cover a top surface of the spacer.
 12. Asemiconductor device comprising: a substrate including a first activeregion, a second active region and a field region, the field regionbeing disposed between the first active region and the second activeregion, the field region directly contacting both the first activeregion and the second active region; an interlayer dielectric layerdisposed on or above the substrate and including a trench; a gatedielectric layer disposed in the trench and including a high-k material,the gate dielectric layer including a first side portion formed on afirst sidewall of the trench, a second side portion formed on a secondsidewall of the trench and a bottom portion formed on a bottom surfaceof the trench; a first metal gate electrode disposed on or above thefirst active region, and disposed on or above the gate dielectric layer;and a second metal gate electrode disposed on or above the second activeregion, and disposed on or above the gate dielectric layer, wherein thefirst metal gate electrode directly contacts the second metal gateelectrode, a depth of the second metal gate electrode is greater than adepth of the first metal gate electrode, a contact surface between thefirst metal gate electrode and the second metal gate electrode is closerto the first active region than to the second active region, and a topsurface of the first metal gate electrode, a top surface of the secondmetal gate electrode and a top surface of the interlayer dielectriclayer are coplanar with each other.
 13. The semiconductor device ofclaim 12, further comprising a work function on which the first metalgate electrode is disposed.
 14. The semiconductor device of claim 12,wherein a width of a first metal gate electrode is less than a width ofthe second metal gate electrode.
 15. The semiconductor device of claim12, wherein a contact surface is disposed on or above the field region.16. The semiconductor device of claim 12, wherein the first metal gateelectrode is a p-type metal gate electrode, and the second metal gateelectrode is an n-type metal gate electrode.
 17. The semiconductordevice of claim 12, wherein the interlayer dielectric layer does notdirectly contact the first metal gate electrode and the second metalgate electrode, and the interlayer dielectric layer is not formeddirectly on or directly above the first active region, the second activeregion and the field region.
 18. The semiconductor device of claim 12,further comprising a spacer disposed between the second metal gateelectrode and the interlayer dielectric layer, wherein a height of thespacer is substantially the same as a distance between a top surface ofthe second metal gate electrode and a bottom surface of the bottomportion of the gate dielectric layer.
 19. The semiconductor device ofclaim 18, wherein the interlayer dielectric layer is disposed on asidewall of the spacer and does not entirely cover a top surface of thespacer.
 20. The semiconductor device of claim 12, wherein the firstmetal gate electrode includes a first upper metal gate electrode and afirst lower metal gate electrode, the second metal gate electrodeincludes a second upper metal gate electrode and a second lower metalgate electrode, the first upper metal gate electrode and the secondupper metal gate electrode are formed with the same material, and thefirst lower metal gate electrode and the second lower metal gateelectrode are formed with the same material.
 21. A semiconductor devicecomprising: a substrate including a first active region, a second activeregion and a field region, the field region being disposed between thefirst active region and the second active region, the field regiondirectly contacting both the first active region and the second activeregion; an interlayer dielectric layer disposed on or above thesubstrate and including a trench; a gate dielectric layer disposed inthe trench and including a high-k material, the gate dielectric layerincluding a first side portion formed on a first sidewall of the trench,a second side portion formed on a second sidewall of the trench and abottom portion formed on a bottom surface of the trench; a gatestructure disposed on or above the gate dielectric layer, the gatestructure crossing the first active region, the second active region andthe field region, the gate structure including a first metal gateelectrode and a second metal gate electrode, the first metal gateelectrode directly contacting the second metal gate electrode; and alayer disposed between the gate structure and the interlayer dielectriclayer, wherein the first metal gate electrode is disposed on or abovethe first active region, the second metal gate electrode is disposed onor above the second active region, a contact surface between the firstmetal gate electrode and the second metal gate electrode is closer tothe first active region than to the second active region, the contactsurface is disposed on or above the field region, a top surface of thelayer between the gate structure and the interlayer dielectric layer iscoplanar with a top surface of the gate structure, and the gatestructure does not directly contact the interlayer dielectric layer. 22.The semiconductor device of claim 21, further comprising a work functionlayer on which the first metal gate electrode is disposed, wherein adepth of the second metal electrode is greater than a depth of the firstmetal gate electrode.
 23. The semiconductor device of claim 21, whereinthe top surface of the gate structure is coplanar with a top surface ofthe interlayer dielectric layer.
 24. The semiconductor device of claim21, wherein the interlayer dielectric layer is disposed on a sidewall ofthe layer between the gate structure and the interlayer dielectriclayer, and the interlayer dielectric layer does not entirely cover thetop surface of the layer between the gate structure and the interlayerdielectric layer.
 25. The semiconductor device of claim 21, wherein thelayer between the gate structure and the interlayer dielectric layer isa spacer, and a height of the spacer is substantially the same as adistance between a top surface of the gate structure and a bottomsurface of the bottom portion of the gate dielectric layer.
 26. Asemiconductor device comprising: a substrate including a first activeregion, a second active region and a field region, the field regionbeing disposed between the first active region and the second activeregion, the field region directly contacting both the first activeregion and the second active region; an interlayer dielectric layerdisposed on or above the substrate and including a trench; a gatedielectric layer disposed in the trench and including a high-k material,the gate dielectric layer including a first side portion formed on afirst sidewall of the trench, a second side portion formed on a secondsidewall of the trench and a bottom portion formed on a bottom surfaceof the trench; a first metal gate electrode disposed on or above thefirst active region, and disposed on or above the gate dielectric layer;and a second metal gate electrode disposed on or above the second activeregion, and disposed on or above the gate dielectric layer; a firstspacer disposed between the first metal gate electrode and theinterlayer dielectric layer; and a second spacer disposed between thesecond metal gate electrode and the interlayer dielectric layer, whereinthe first metal gate electrode is disposed on or above the first activeregion, the second metal gate electrode is disposed on or above thesecond active region, a width of a first metal gate electrode is lessthan a width of the second metal gate electrode, a contact surfacebetween the first metal gate electrode and the second metal gateelectrode is closer to the first active region than to the second activeregion, the contact surface is disposed on or above the field region, atop surface of the first spacer is coplanar with a top surface of thefirst metal gate electrode, a top surface of the second spacer iscoplanar with a top surface of the second metal gate electrode, and theinterlayer dielectric layer is disposed on a sidewall of the firstspacer and on a sidewall of the second spacer, and does not entirelycover the top surface of the first spacer and the top surface of thesecond spacer.
 27. The semiconductor device of claim 8, wherein thefirst upper metal gate electrode and the second upper metal gateelectrode include at least one of Al and W, and the first lower metalgate electrode and the second lower metal gate electrode include atleast one of TiN, TaN, TaC, TaCN, TiAl, and TiAlC.
 28. The semiconductordevice of claim 20, wherein the first upper metal gate electrode and thesecond upper metal gate electrode include at least one of Al and W, andthe first lower metal gate electrode and the second lower metal gateelectrode include at least one of TiN, TaN, TaC, TaCN, TiAl, and TiAlC.29. The semiconductor device of claim 21, wherein the first activeregion is a PMOS forming region, and the second active region is an NMOSforming region.
 30. The semiconductor device of claim 21, wherein awidth of a first metal gate electrode is less than a width of the secondmetal gate electrode.